- For other uses, see Bortas.
The bortaS bIr-class was a Klingon starship class, a battleship in service to various Great Houses of the Klingon Empire in the 2250s decade. (DSC episode: "Battle at the Binary Stars", ST Issue The Official Starships Collection: "DSC01")
This was one of four Klingon attack ship classes, all variants of the same basic spaceframe. Besides the bortaS bIr, the other Klingon attack ship classes were Qaw', Qoj and veqlargh. The ship consisted of a spear-like elongated primary hull, framed by a pair of long, bulky and forward-facing warp nacelles with weapon ports. The nacelles and neck section were connected by a compact engineering hull marked with a circle and impulse engines at its stern. (ST Issue The Official Starships Collection: "DSC10"
Several vessels of this class fought in the war between the Federation and Klingon Empire, also known as Burnham's War, starting with the Battle of the Binary Stars in May 2256. (DSC episode: "Battle at the Binary Stars")
In November 2256, General Kol, son of Kol-Sha, traveled aboard a BortaS bir-class ship to claim the crippled Sarcophagus at the binary system. (DSC episode: "The Butcher's Knife Cares Not for the Lamb's Cry")
In 2257, a pair of bortaS bIr-class battleships were part of an armada gathering in the Sol system to attack Earth. The armada disengaged and returned to Klingon space when Chancellor L'Rell ended the war. (DSC episode: "Will You Take My Hand?")
In 2410, the temporal displacement of J'Ula and many of her forces of House of Mo'Kai from the Defense of Starbase 1 to present-day, the bortaS bIr class returned service. (STO - Age of Discovery mission: "Downfall")
Ships of the class, including from a 2256-era mirror universe, were involved with transtemporal events instigated by Sylvia Tilly at Pahvo. (STO - Mirror of Discovery missions: "Para Pacem", "Illusion of Communication", "Peril at Pahvo")